alleles
the different forms/versions of a gene (letters)
Alleles are alternate forms of a gene that occupy the same position on a chromosome. These alternate forms arise from mutations that occur in the DNA sequence of a gene. Each individual inherits two alleles for each gene, one from their mother and one from their father.
Alleles can be dominant or recessive. A dominant allele produces a visible trait, even when only one copy is present. This means that if an individual inherits one dominant allele and one recessive allele, they will display the dominant trait. On the other hand, a recessive allele is only expressed when an individual inherits two copies. If an individual inherits two recessive alleles, they will display the recessive trait.
Genetic variation in a population arises from the presence of multiple alleles at a particular locus. For example, blood type is determined by multiple alleles of the ABO gene, which encode different versions of the enzyme that attaches specific sugar molecules to the surface of red blood cells. Different combinations of these alleles result in different blood types.
Overall, the presence of multiple alleles in a population allows for genetic diversity and can provide the basis for natural selection and evolution.
More Answers:
Homozygous Dominant: Definition, Examples, and Relevance in GeneticsRecessive Alleles: Explaining Inheritance Patterns and Genetic Conditions
Dominant Alleles: A Comprehensive Guide to Genetic Variants and Phenotype Expression